Vulnerability in Kernel (CVE-2025-21821)

Summary

Vulnerability in Kernel (CVE-2025-21821). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.1.129, 6.6.79, 6.12.16, 6.13.4 or later.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved:

fbdev: omap: use threaded IRQ for LCD DMA

When using touchscreen and framebuffer, Nokia 770 crashes easily with:

BUG: scheduling while atomic: irq/144-ads7846/82/0x00010000
Modules linked in: usb_f_ecm g_ether usb_f_rndis u_ether libcomposite configfs omap_udc ohci_omap ohci_hcd
CPU: 0 UID: 0 PID: 82 Comm: irq/144-ads7846 Not tainted 6.12.7-770 #2
Hardware name: Nokia 770
Call trace:
 unwind_backtrace from show_stack+0x10/0x14
 show_stack from dump_stack_lvl+0x54/0x5c
 dump_stack_lvl from __schedule_bug+0x50/0x70
 __schedule_bug from __schedule+0x4d4/0x5bc
 __schedule from schedule+0x34/0xa0
 schedule from schedule_preempt_disabled+0xc/0x10
 schedule_preempt_disabled from __mutex_lock.constprop.0+0x218/0x3b4
 __mutex_lock.constprop.0 from clk_prepare_lock+0x38/0xe4
 clk_prepare_lock from clk_set_rate+0x18/0x154
 clk_set_rate from sossi_read_data+0x4c/0x168
 sossi_read_data from hwa742_read_reg+0x5c/0x8c
 hwa742_read_reg from send_frame_handler+0xfc/0x300
 send_frame_handler from process_pending_requests+0x74/0xd0
 process_pending_requests from lcd_dma_irq_handler+0x50/0x74
 lcd_dma_irq_handler from __handle_irq_event_percpu+0x44/0x130
 __handle_irq_event_percpu from handle_irq_event+0x28/0x68
 handle_irq_event from handle_level_irq+0x9c/0x170
 handle_level_irq from generic_handle_domain_irq+0x2c/0x3c
 generic_ha…

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2025-21821 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.1.129, 6.6.79, 6.12.16, 6.13.4 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-21821" on the vendor's site.

CVE-2025-21821 (Kernel)
Patched: 6.1.129, 6.6.79, 6.12.16, 6.13.4 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in Kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Kernel.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 6.1.129, 6.6.79, 6.12.16, 6.13.4.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Kernel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'Kernel' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Kernel を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade Kernel to 6.1.129, 6.6.79, 6.12.16, 6.13.4
```
ステージング環境で 6.1.129, 6.6.79, 6.12.16, 6.13.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"5.19.0"},{"fixed":"6.1.129"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.79"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.16"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.13.4"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-21821 linux-lts Fixed in: 6.1.130-r0
Debian DEBIAN-CVE-2025-21821 linux Fixed in: 6.1.129-1
Ubuntu UBUNTU-CVE-2025-21821 linux